This article reviews the practical experiments on the effects of ultra violet light on paper conducted in the hall of the former Archives of L'Oise at Beauvais during the summer of 1958 under the control of engineers of the Saint Gobin Company. It further compares them to the results of tests conducted at the Research Center of the Saint Gobin Company at La Croix de Berny during 1959. The 1958 test, used several paper samples of various ages and quality subjected to light through ordinary glass and two types of inactinic glass. Results indicate that samples exposed to light through the inactinic glass which filters out the ultra violet rays, sustained a lesser amount of damage than those exposed to unfiltered light. The 1959 experiments, using more rigorous test, as well as an additional type of glass tinted yellow with cadmium sulfide, confirmed the 1958 findings and showed the cadmium sulfide glass to be the most effective filter in retarding light damage to documents in storage.